From codex
A child theme is a theme that inherits the functionality and styling of another theme, called the parent theme. Child themes are the recommended way of modifying an existing theme.
Benefits of using Child Theme
- If you modify a theme directly and it is updated, then your modifications may be lost. By using a child theme you will ensure that your modifications are preserved.
- Using a child theme can speed up development time.
- Using a child theme is a great way to learn about WordPress theme development.
Customize Child Theme
All customizations are stored in the child theme and anything in the child takes priority over the parent. So if the same file exist in both child and parent, the file from the child will control that aspect of the theme.
All our themes ships with a child theme. Just install [theme name]-child.zip. Then, you can change the files as your need without changing anything in parent theme.
like if you change assets/css/style.css file then move same folder structure in child theme assets/css/style.css